PROJECT SUMMARY This renewal application seeks continuing support for the ?Microenvironmental Influences in Cancer? Training Program (MICTP) at Vanderbilt University. Over the past 30 years and continuing withthe 5-year period preceding this competitive renewal, we have been remarkably successful in recruiting and training excellent students and postdoctoral fellows, particularly those from groups underrepresented in science. Based on the strength of our training faculty, in the next five years we will focus on training our students and postdoctoral fellows in emerging areas of tumor microenvironment, including single cell approaches to understand the complexity of the microenvironment, bioinformatics and quantitative analysis of large datasets, tumor immunology and immunotherapy, hypoxia and blood vessel normalization, and extracellular vesicles. Overall, the MICTP training program encompasses a group of 24 faculty members from the Vanderbilt University School of Medicine who are experts in research on tumor microenvironment. The training program is conducted within a vibrant academic environment and is supported by close interactions with the Vanderbilt-lngram Comprehensive Cancer Center. In addition to preceptor-specific laboratory instruction, each trainee receives program- specific training in the form of (1) Topical workshops, which introduce trainees to emerging fields of the tumor microenvironment; (2)?Cancer Precision Medicine? course that includes an individualized clinical experience, (3) a bi-weekly T-32 Scientific Forum with trainee ?chalk talk? and faculty presentations, (4) an annual MICTP mini-retreat, and (5) a five-session grant workshop. Faculty preceptors also receive training to be culturally aware good mentors. Furthermore, predoctoral students are supported by an Interdisciplinary Graduate Program and a graduate program in Cancer Biology. Postdoctoral trainees are supported by an institutional Office of Postdoctoral Affairs, which provides both financial and academic support as well as career development advice and opportunities. Significant institutional investment in training programs, core facilities, state-of-the-art laboratories and equipment further enhances trainee development. Training in this critical area of cancer research is essential to build the workforce required to understand the complexities of the microenvironmental influence on cancer development and progression, and to translate this information into more effective and less toxic approaches to the treatment and prevention of cancer.